How do you express the fractions 12/316 and 7/8 using a least common denominator (LCD)?

To express the fractions 12/316 and 7/8 with a least common denominator (LCD), follow these steps:

Step 1: Determine the Denominators

The denominators of our fractions are 316 and 8.

Step 2: Find the Prime Factorization

Next, we need to find the prime factorization of each denominator:

  • 316: It can be factored as follows:
    • 316 = 2 × 158
    • 158 = 2 × 79
    • So, 316 = 2² × 79
  • 8: The prime factorization is:
    • 8 = 2 × 2 × 2 = 2³

Step 3: Identify the Least Common Denominator

The LCD is determined by taking the highest power of each prime factor found in the factorizations. Here, we find:

  • For the prime factor 2: highest power is (from 316) and (from 8), so we take .
  • For the prime factor 79: highest power is 79¹ (from 316).

Therefore, the LCD = 2³ × 79¹ = 8 × 79 = 632.

Step 4: Convert Each Fraction

Now we can convert each fraction to have the least common denominator of 632.

  • For 12/316:
    • To convert 12/316, we multiply both the numerator and the denominator by 2:
    • 12 × 2 = 24
    • 316 × 2 = 632
    • So, 12/316 = 24/632.
  • For 7/8:
    • To convert 7/8, we multiply both the numerator and the denominator by 79:
    • 7 × 79 = 553
    • 8 × 79 = 632
    • So, 7/8 = 553/632.

Final Result

Thus, both fractions expressed with the least common denominator are:

  • 12/316 = 24/632
  • 7/8 = 553/632

This way, we have successfully expressed both fractions using the least common denominator!

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